PSYC 450 Drugs and Behaviour final exam actual
questions and answers online solution Athabasca
University
, PSYC 450 Drugs and Behaviour final exam actual questions and answers online solution Athabasca
University
Compare and contrast the function of autoreceptors and transporters. - --Autoreceptors, located in
the membrane of presynaptic nerve cells. Autoreceptors can be found on any part of the cell
membrane, the Soma, dendrites, axon, or axon terminal. Auto receptors are usually G protein-coupled
receptors, therefore act via a second messenger rather than gated ion channels. It is only sensitive to
the neurotransmitters or hormones released by the neuron on which the autoreceptor sits.
Transporters, proteins that carry neurotransmitters across cell membranes. Synaptic Transporters
remove neurotransmitters and halt their actions, but Transporters can also carry neurotransmitters
into the synapse, allowing them to bind to receptors and cause and effect.
Name the major serotonin cell clusters in the brainstem and describe their projection pathways. - --
Most of the serotonergic neurons in the central nervous system are found along the middle of the
brainstem associated with cell clusters called the raphe nuclei. The dorsal raphe nuclei and the
median raphe nuclei send serotogenic fibers to almost all of the areas in the forebrain. Almost all
forebrain regions, including the neocortex, striatum and nucleus accumbens, thalamus,
hypothalamus, hippocampus and amygdala, receive serotonin supply from the raphe nuclei.
Distinguish between short-term excitotoxic effects of glutamate and the delayed type of cell death
called apoptosis. - --Excitotoxicity: when nerve cells are damaged by prolonged exposure to
glutamate,(necrosis). Excessive exposure to glutamate can damage and sometimes kill nerve cells
through depolarization of the cell. However, if overexposure to glutamate, or the amount of time the
cell is exposed is reduced, the cells return to a normal state. In humans, excitotoxic cell death can be
caused by ingesting food contaminated with demonic acid or through stroke and traumatic brain
injury. Traumatic cell death.
Apoptosis, a delayed cell death which involves disruption of the cell nucleus and breakdown of DNA.
It's a biochemical process of programmed cell death. Occurs normally during fetal brain development.
Excitotoxic treatments may also activate apoptosis. Biologically controlled cell death.
Define the therapeutic index and describe how it is calculated and why it is important. - --The
therapeutic index calculate drug safety. It compares the amount of drug that causes a therapeutic
effect to the amount that causes toxicity in most people. The therapeutic index is determined by
taking the ED50 ( the dose of a particular drug that produces 50% of the maximum effect) and
comparing it with the TD 50, 50% toxic dose, or the dose at which 50% of the population experiences a
Toxic effect. This information is plotted on a dose-response curve. The therapeutic index is important
when considering the benefits versus risk of serious side effects for people who might use the drug.
, Name and briefly describe the functions of the four lobes of the cerebral cortex - --Occipital lobe, the
primary visual cortex. Visual reception and interpretation.
Perietal lobe, primary somatosensory cortex. Sense of touch, taste and smell. Spatial perception.
Temporal lobe, primary auditory cortex. Understanding language.
Frontal lobe, primary motor cortex. Movement and executive planning.
Explain what is meant by face, predictive, and construct validity. Which is most important for the
development of clinically useful medications - --Construct validity refers to the extent to which there
is evidence that a test measures a specific hypothetical construct. IE the extent to which animal
behavioral measurement tools actually measure the target behavior in the animal.
Face validity refers to the degree to which an assessment or test appears to measure the variable it is
supposed to measure. Being able to transfer testing / results from inside the lab to other
environments with similar results. IE blood pressure tests on lab animals, resemble those tests used
for humans.
Predictive validity refers to the extent to which a score on a scale or test predict scores on a Criterion
measured. I e drug effects observed in a lab predict clinical effect of the drug.
Describe the components of the cyclical pattern of pathological drug use and how it can lead to
addiction. Be specific with regard to how the DSM-5 criteria fit into this model. - --Pattern has three
components:
1, periods of preoccupation with drugs and anticipation of upcoming use.
2, periods of drug intoxication that may be associated with binging on the drug.
drug.
3, periods following drug use that are marked by withdrawal symptoms and negative effect.
Overtime, repeating this cycle, as well as taking drugs and larger amounts than intended and
development of drug tolerance, leads to a downward spiral that can ultimately result in addiction.
Nearly taking a drug does not indicate a substance use disorder. The use must be maladaptive, or
cause harm to the user, as indicated in the DSM. The cyclical Model includes some of the features that
